Multi-position Weight Down Tool with Directional Lugs
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Solution Overview
Problem
In oil and gas well operations, existing tools face challenges in accurately locating and applying weight to specific zones within a wellbore, leading to potential damage and inefficiency during gravel packing and fracturing processes due to the lack of precise engagement mechanisms and wear on wellbore components.
Innovation Solution
A weight down tool system featuring a central mandrel with radially expandable lugs and an indicator that selectively engages restrictions in the wellbore, allowing for precise weight transfer and reduced wear by expanding and retracting lugs based on directional movement, utilizing a keyed profile for selective actuation and minimizing contact with non-target restrictions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a workover assembly is supported at or near the zone being treated, then the weight can be applied to the restriction, but the tool cannot easily be moved to treat multiple zones without additional trips
Solution Approach 1:
The weight down lugs are designed to be dynamically adjustable between engaged and disengaged states. When moving to a new zone, the lugs are retracted to allow passage through restrictions. When treating a zone, the lugs expand to engage the restriction and apply weight. This dynamic capability enables the tool to treat multiple zones in a single trip by sequentially engaging different restrictions.
2Ease of operation
If the lugs are constantly engaged with restrictions, then weight can be applied, but the tool cannot be moved through the wellbore to reach different zones
Solution Approach 1:
The lugs incorporate a mechanical system that allows them to transition between engaged and disengaged states based on directional movement. During downward movement, the lugs are forced into engagement with the restriction. During upward movement, the lugs are forced into disengagement. This dynamic behavior automatically provides both mobility during tool movement and reliable weight application during zone treatment.
3Manufacturing precision
If the tool engages all restrictions encountered, then weight is applied at every point, but this causes excessive wear on wellbore components and prevents precise zone targeting
Solution Approach 1:
The tool employs different lug types with specific local functions: hunter lugs are positioned to engage only specific target restrictions for weight application, while lockout lugs engage non-target restrictions to prevent premature activation. This local differentiation allows the tool to selectively apply weight only at intended zones, minimizing wear on wellbore components and achieving precise zone targeting.
4Ease of operation
If the indicator remains outwardly extending, then it can engage restrictions easily, but it causes excessive wear on restriction surfaces during downward movement
Solution Approach 1:
The indicator is designed to dynamically change its radial position based on movement direction. During downward movement, the indicator retracts inward to minimize contact and wear on restriction surfaces. During upward movement, the indicator extends outward to engage the restriction and activate the weight down lugs. This dynamic positioning reduces wear during tool installation while maintaining engagement capability during operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables efficient and precise weight application to specific zones within the wellbore, reducing wear on components and allowing for multi-zone treatment in a single trip, improving the accuracy and efficiency of gravel packing and fracturing operations.
Implementation Method 1
a plurality of radially expandable weight down lugs configured to selectively transition between an expanded position and a retracted position
Implementation Method 2
the indicator is configured to retract inwards in response to moving through one or more of the plurality of restrictions in a downwards direction
Implementation Method 3
the weight down lugs are configured to retract to the refracted position in response to the weight down lugs moving through one or more restrictions of the plurality of restrictions in an upwards direction
Data Source
AI summary
A weight down tool comprises a central mandrel configured to be coupled to a wellbore tubular, an outwardly extending indicator disposed about the central mandrel, and a plurality of radially expandable weight down lugs configured to engage a lower restriction and prevent downwards movement of the central mandrel with respect to the lower restriction when disposed in an expanded position. The indicator is configured to retract inwards in response to moving through an upper restriction in a downwards direction to expand the weight down lugs into the expanded position in response to moving through the lower restriction in an upwards direction. The weight down lugs are configured to retract out of the expanded position in response to moving through the upper restriction in an upwards direction.